Air thrust boat



Aug. 9, 1960 FIG.

F. M. PETERSON 2,948,250

AIR THRUST BOAT Filed March "I. 1955 FRED M. PETERSON uvwzzvrox. I BY W@ww TTORNEY United StatesiPatent- O 2,948,250 7 Am 'rnRUs'r Bert v FredM. Peterson, 3308 Mohawk Trail, Fort Worth, rm Filed Mar. 7, 1955, set."No. 492,395

p 2 Claims. (ct. its-.5

This invention relates to airthrust propeller driven boats and hasreference to a steering mechanism therefor.

Boats of the air thrust propeller driven type have found wideapplication and accepance in areas where'shallow water, reeds,everglades andsub-surface debrispresent hazards to the operation ofsubmerced propellers.

2,948,250 Patented Aug. 9,

ice

peller shaft 15. The driving pulley 14is direetlyeconnected withthe'engine 11, whereas the driven pulley 13 is mounted on the propellershaft 15. The vertical sup port 16 is constructed and'positioned so thatits'upper portion lies in a straight linebetween the centers of thedriving pulley 14 and the'driven pulley 13, whereas its lower portionextends 'downwardbending away from'the driving pulley 14-toward thetransom' 17 of the boat. A cylindrical opening 18 is provided within theupper end of the vertical support 16, and acoil spring 19 is recessedtherein and supported by abolt 20. -Journaled into the cylindricalopening 18 and supported on the spring 19 is a pivot shaft 21, the axisof which is coincident with a straight ,line extendingjthrough the.centers of the pulleys '13- and "14, and perpendicular to theaxes ofrotation of pulleys 13 and 14. The U-shaped propeller 5 shaft bearingmount 22 is afiixedat its base to the top Steering of boats drivenbyfair th'rust propellers is I generally accomplished byrudders ofeither the c'onventional boat type submerged in-water or theai'rcrafttype mounted in the slipstream of the air thrust propeller. Theoperation of the former is objectional because any submerged movablepart is subject to the previously mentioned hazards; steering by thelatter is sluggish and ineflicient since it is dependent upon deflectionof a dissipating slipstream of air.

Another method of steering air thrust propeller driven boats consists ofchanging the direction of thrust by rotating both engine and propellerabout a vertical axis. This method has never received wide acceptancebecause the consequent elevated mounting of a heavy engine high abovethe water line of a boat greatly decreases that boats lateral stabilityand presents a safety hazard when of the pivot shaft 21 andjshaped withbearing ends '23 and 24 extending upwardequally from its'base a distancegreater'than the radius 'of'driven pulley 13, fI'he propellerishaft 15aflixed to the propeller 10 is journaled in thejends of the" U-shapedpropellershaft bearing m ount 22 so'tbat its axis of rotation isperpendicular to'the of rotation of the pivot shaft 21. The drivenpulley 13 is mounted on the propeller shaft 15 and affixed theretobetween the upward extending ends 23 and 24 of the bearing mount 22. Thespring 19 urges the pivot shaft 21 upwardly providing a space a betweenthe upper end of the vertical support 16 and the lower end of thebearing mount 22. A tiller 25 is pivotally attached in a vertical planeto the U-shaped propeller shaft bearing mount 22 near its base at theend of said mount ope posite to and extending away from the propeller10. The base of the vertical support 16 is afllxed to an inwardlyprojecting L-shaped engine mounting bracket 26 which is pivotallyattached in a vertical plane to a transom clamp 27 and suspendedtherefrom by an adjustable pin 28 and pivoted parallel links 29 havingpin receiving A further object of this invention is to provide meanswhereby the center of gravity of air thrust propeller driven boats maybe lowered in such a way as to make possible safe changes in thedirection of propeller thrust force relative to the boat, therebyaccomplishing a practical means of utilizing thrust force for steeringpurposes.

A further object of this invention is to' provide a prepeller assemblyfor the purpose of driving and steering an air thrust boat which may berotated about a vertical axis independent of the position of its primemover and which may be detached from that prime mover without the use oftols for purposes of portability.

In the drawings:

Figure 1 is a side elevation of the device attached to a boat, only afragmentary portion of the latter being shown.

'Figure 2 is a plan view of the same with the propeller shaft brokenaway and propeller, motor and transom clamp deleted.

Referring to the drawings, it will be noted that the holes 30 therein.ports the engine 11 in a horizontal position beneath and forwardly ofthe U-shaped propeller shaft bearing mount 22.

In operation the direction of thrust as developed by the propeller 10relative to the position of the boat may be altered by rotating thepropeller shaft bearing mount 22 about its vertical axis by means of thetiller 25. The low position of the weight of the engine 11 with respectto the center of gravity of the boat permits this change of thrustdirection to be used effectively for steering purposes without loss oflateral stability and the commensurate danger of capsizing. Rotation ofthe propeller shaft bearing mount 22 by means of the tiller 25 resultsin a decrease in the effective length of the V belt 12 and acorresponding decrease in the distance between the pulleys 13 and 14causing an increased compression in the spring 19 which supports thepivot shaft 21. When the tiller 25 is released from its rotated positionthe pressure from the compressed spring 19 forces the V- elt 12 back toits longest effective-length which exists w en the axis of rotation ofthe driving pulley 14 is parallel to the axis of rotation of thepropeller 10.

When this device is not in use it is so constructed as to permitdismantling without tools into two portable assemblies by pulling downon the V belt 12 to compress the spring 19, thereby removing tensionfromthe belt in its lower part sothat it may be disengaged from the lowerpulley 14.. The upper assembly consisting of the propeller 10, safetyframe 30, propeller shaft 15, driven pulley 13, propeller shaft bearingmount 22, tiller 25, V belt 12 and pivot shaft 21 may then be liftedfrom the vertical support 16 and carried as a separate unit. 1

The engine mounting bracket 26 supa a I This invention is not limited tothe exemplary construction herein shown and described, but may be madein various ways within the scope of the appended claims.whatisclainiedisz e '2 i 1. A'steering device for an air thrustpropeller driven boat, said steering device including a vertical supportcarried by said boat and'extendingxupwardly thereabove, avertical'pivot-shaft rotatably received in the upper end of saidvertical support, a bearing mountrotatably mounted in the upper end ofsaid vertical shaft, a horizontal shaft journalled in said bearing mountand adapted to support and rotate the propeller, a driven pulley mountedon said horizontal shaft and positionedover the axial center of theupper end of said vertical shaft, a drive pulley beneath the upper endof said vertical shaft and in alignment with the axis of-said shaft, abelt around said pulleys and positione'd outwardly of andalong oppositesides of said vertical support andsaid pivot'shaft, and a tillerconnected with said bearing mount.

2. A steering device for an air thrust propeller driven boat, saidsteering'device including a vertical support carried by said boat andextending-upwardly thereabove, a vertical pivot shaft rotatably receivedin the upper end of said vertical support, a bearing mountrotatablymounted in the upper end of said vertical pivot shaft, a horizontalshaft journalled in said bearing mount and adapted to support and rotatethe propeller, a driven pulley mounted on said horizontal shaft andpositioned over the axial center of the upper end of said verticalshaft, a drive pulley beneath the upper end of said vertical shaft andin alignment with the axis of said shaft, a belt around said pulleys andpositioned outwardly of and along opposite sides of said vertical"support and said pivot shaft, a tiller connected with said bearingmount, and an L- shaped engine mounting bracket adapted to be moturtedon'the transom of a boat; saids L-shaped engine mounting bracket havingan engine mounted thereon, the lower end of said vertical supportbe'ingmounted on said engine mounting bracket,,said drivingpulley beingmounted to be driven by the crank shaft of said engine.

436,555; Great Britain Oct. 14, 1935

